Average Service Years calculation with mutiple record in Bex 3.5 Report

Hi Experts,

I have a report requirement were i am not getting the desired result. Most of the time i search through forum and find my way. But this time i am having a tough time finding solution.

Here is the requirement.

I have to create a report to display the average service years. Sample report

Org Unit Employee Education No of Employee Service Years Average Service Years

20002133 10050981 Bachelors 1 40 40

10050981 Masters 1 40 40

20002134 10034567 Bachelors 1 22 22

10034567 Masters 1 22 22

10034567 Technical 1 22 22

-

2 62 31 (desired result )

I am using a simple formula (Total Service years / no of employee ). However i am not getting the desired result. In my case, the service years is getting added i.e (40+ 40 +22 + 22 + 22 = 146 ) and then gets divided by 2 as a result i get 73 as the average service years.

We are using BW 3.5 Query Designer Which have very limited functionality.

So, Guys if anyone have a solution or any suggestions to work on this? Any help greatly appreciated..